Considering the great popularity of eccentric-based training, the purpose of this review is to first provide the scientific rationale for its use; second, summarize the eccentric-based training modalities that can be used; and finally, offer practical recommendations on how to implement eccentricbased modalities to enhance sports performance. The molecular and neural mechanisms underlying eccentric actions are partially distinct from those of concentric and isometric actions. During eccentric actions, theories suggest a strain-induced modulation of actin-myosin interactions at the crossbridge level, activation of structural protein titin, and winding of titin on actin. Eccentric acute physiological responses differ from concentric exercise responses, including variations in neuromuscular, metabolic, hormonal, and anabolic signaling. Eccentric training elicits greater improvements in muscle strength, power, and stretch-shortening cycle function compared with concentric-only or traditional resistance training. Therefore, eccentric-based training can lead to unique neuromuscular (e.g., improved coordination of motor units) and morphological (e.g., increased muscle fascicle length and enhanced distal cross-sectional area) adaptations that could play a key role in sport performance. Practitioners may implement eccentric exercises with external loads, fully eccentric-based exercises (e.g., Nordic hamstring curl), accentuated eccentric loading, flywheel resistance exercise, and plyometrics to develop specific physical adaptations in line with their goals. Eccentric work (e.g., for hamstrings) can be obtained during other exercises such as downhill running tasks, decelerations, and sprinting activities. Practitioners need to be aware that no single “silver bullet” training modality exists; consequently, practitioners should use a combination of eccentric-based training approaches with their athletes to obtain the desired adaptations.

Acceleration is the rate of change in velocity, so this phase of sprinting is critical for changing directions as rapidly and efficiently as possible. Optimal technique for linear sprinting in the acceleration phase involves four factors that maximize stride length and frequency.

This article highlights the scientific evidence on exercises like the seated leg extension, leg curl, and adduction machines to highlight their potential benefits on enhanced performance and potentially reducing injury risk.

The purpose of this article is to provide personal trainers with a review of common muscle extensibility tests of the lower extremity.

The squat is one of the most widely used exercises in resistance training programs. The aim of this narrative review was to analyze the effect of the squat on lower-limb muscle hypertrophy. Briefly, the available literature indicates that the squat is an effective exercise for inducing hypertrophy of the quadriceps, mainly the vastii, but also the rectus femoris, although to a reduced magnitude. Multiple lines of evidence suggest little to no hamstring hypertrophy from the back squat. Although the gluteus maximus clearly participates mechanically in the back squat, few longitudinal studies exist on the topic. The limited evidence available on this topic suggests deeper squats may be more hypertrophic for the gluteus maximus, and that, squat depth beyond 908 of knee flexion may not provide further hypertrophy of the knee extensors. Despite the popularity of the many squat variations, there are still controversies surrounding their hypertrophic potential for lower-limb musculature. Further studies are needed to investigate the hypertrophic effects of different squat variations, as well as differences in hypertrophy because of squat depth, stance, barbell position, and different squat apparatuses/machines.

Review assessment protocols for military personnel, firefighters, and police officers from NSCA’s Essentials of Tactical Strength and Conditioning, 2nd Edition.

Olympic-style lifting, functional training, powerlifting, and bodybuilding should all be considered when designing a program to improve general health, fitness, and functional capacity.

This excerpt from Developing Speed aims to develop athletes’ ability to accelerate quickly through stride modification.

The NFL Combine is a week-long evaluation process that allows NFL scouts, coaches, general managers, and owners to get an up-close and personal evaluation of the talent that comprises the given year’s draft class. This is a day-by-day program outline to maximize results and effort for the NFL combine.

Deceleration in court and field sports, such as football and soccer, is an important component of speed and agility. This book excerpt looks at how to train for effective deceleration.